实体框架：当使用函数导入更新并在存储过程中重新选择实体时，实体被缓存 [英] Entity Framework: Entity is cached when update and reselecting it in a stored procedure using a function import

问题描述

我在Visual Studio 2010和SQL Server 2008 R2中使用EF4。

I'm using EF4 with Visual Studio 2010 and SQL Server 2008 R2.

我正在选择一个实体。之后，我调用更新该实体的存储过程，从数据库重新选择该实体。当我在代码中捕获存储过程的结果时，我看到旧的（以前选择的）属性。

I am selecting an entity. After that I call a stored procedure which updates that entity en reselects it from the database. When I catch the result of the stored procedure in code, I see that the old (previously selected) properties.

显然我正在查看缓存的实体值。有没有办法来证明我的实体更新了EF？或者是某种魔法属性？

Obviously I'm looking at the cached entity value. Is there a way to signal EF that my entity was updated? Or a magic property of some sort?

我的数据库表（和实体）看起来像这样：

My database table (and entity) look something like this:

CREATE TABLE [Message]
(
    ID int IDENTITY(1, 1) PRIMARY KEY,
    Content XML,
    StateID int NOT NULL,
)

我的SP是这样的：

CREATE PROCEDURE sp_Queue_s
AS
BEGIN
    DECLARE @queue table ([ID] int NOT NULL)
    BEGIN TRAN
        INSERT INTO @queue
        SELECT [ID]
        FROM [Message]
        WHERE   StateID = 1

        UPDATE [Message]
        SET StateID = 2
        WHERE ID IN (SELECT ID FROM @queue)
    COMMIT TRAN
    -- Select the queue
    SELECT [ID], [Content], [Message]
    FROM [Message]
    WHERE [ID] IN (SELECT ID FROM @queue)
END

我的C＃代码看起来像这样：

My C# code looks something like this:

using (var context = new MyEntities())
            {
                int id = 1;
                var message = context.Messages.Single(m => m.ID == id);
                var messages = context.GetQueue(); // Function import of sp_Queue_s, maps on the Message entity
                var messageUpdated = messages.Single(m => m.ID == id);
            }

推荐答案

GetQueue 应该是内部调用 context.ExecuteFunction 的生成方法。 ExecuteFunction 有多个重载，其中一个接受 MergeOption 。尝试使用 MergeOption.OverwriteChanges 直接调用 ExecuteFunction 。

GetQueue should be a generated method internally calling context.ExecuteFunction. ExecuteFunction has multiple overloads and one of them accepts MergeOption. Try to call ExecuteFunction directly with MergeOption.OverwriteChanges.

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